I understand this is less of a hobo question but I am hoping for a hobo
solution since it seems it is a lacking in rails.
named_scope :not_commented_by, lambda { |u| { :include
=> :comments, :conditions => ['comments.owner_id != ? OR comments.id
IS NULL', u.id] } }
Falls apart once there are 2 or more comments.
On Tue, Nov 10, 2009 at 9:06 PM, christian <[email protected]> wrote:
> Anyone have any idea why
>
> named_scope :not_commented_by, lambda { |u| { :include
> => :comments, :conditions => ['comments.owner_id != ? OR comments.id
> IS NULL', u.id] } }
>
> this would effectively show comments from a user if they haven't commented
> or if there are not comments but when they do comment and then someone else
> comments the entry shows back up in the table again.
>
>
> On Mon, Nov 9, 2009 at 8:57 PM, christian <[email protected]> wrote:
>
>> I have implemented the named scoped method after carefully trying the
>> other methods to get a better understanding.
>>
>> In the named scope method you use u which is short for users? I wasn't
>> sure about the 'u' but I do understand the lambda and now better understand
>> when to utilize a named scope.
>>
>> I am still having an issue with the not commented by portion, as it seems
>> to to ignore it once another person has commented.
>>
>> Thanks for all your help.
>>
>>
>> On Tue, Nov 10, 2009 at 3:29 AM, Matt Jones <[email protected]> wrote:
>>
>>>
>>>
>>> On Nov 9, 2009, at 9:36 PM, christian wrote:
>>>
>>> > When I try to use @user.id I get the following error
>>> >
>>> > "Called id for nil, which would mistakenly be 4 -- if you really
>>> > wanted the id of nil, use object_id"
>>> >
>>> > Is there something else I would have to change in order for it to
>>> > work without the object_id ?
>>> >
>>>
>>> The problem is that you're looking at @user before it is set. Code
>>> that needs the instance should be in the hobo_show block rather than
>>> ahead of it.
>>>
>>> So your controller would look like
>>>
>>> def account
>>> # @user is nil here
>>> hobo_show do
>>> # do something with @user here
>>> end
>>> end
>>>
>>> On the genre issue, if Genres aren't being regularly created, it's
>>> better to keep them as an enum_string rather than cluttering things
>>> with an extra association. Certainly, if you keep the Genre table, you
>>> shouldn't *ever* specifically code a value for the id field - using
>>> Genre.find_by_name('Prose') would be much more resilient to DB changes
>>> and so on.
>>>
>>> With the genre table, one way to write the query you're looking for is:
>>>
>>> @prose = Genre.find_by_name('Prose').submissions.find(:all, :include
>>> => :comments, :conditions => ['comments.owner_id != ? OR comments.id
>>> IS NULL', @user.id])
>>>
>>> The "comments.id IS NULL" part is SQL's weird way of saying "there
>>> isn't a record"; for instance, this will find all submissions with NO
>>> comments:
>>>
>>> @no_comments_at_all = Submission.find(:all, :include
>>> => :comments, :conditions => 'comments.id IS NULL')
>>>
>>> It looks really weird at first (since comments.id *can't* be null),
>>> but is a result of the outer join that :include does; records in
>>> 'submissions' that don't have any associated records joined against an
>>> 'all null' row. comments.id in the above could actually be any field
>>> that's guaranteed not to be null in real records, but the convention
>>> is to use 'id' (since you've got other problems if you've got nil id
>>> records...).
>>>
>>> As a final note, I'd still recommend that you roll a chunk of this
>>> logic into named scopes, thus:
>>>
>>> class Submission
>>> ...
>>> named_scope :not_commented_by, lambda { |u| { :include
>>> => :comments, :conditions => ['comments.owner_id != ? OR comments.id
>>> IS NULL', u.id] } }
>>> end
>>>
>>> This cleans up the @prose find to:
>>>
>>> @prose = Genre.find_by_name('Prose').submissions.not_commented_by(@user)
>>>
>>> Good named scopes end up reading almost like a sentence; even a Ruby
>>> novice would have a good chance of figuring out what the statement
>>> above does.
>>>
>>> Hope this helps!
>>>
>>> --Matt Jones
>>>
>>>
>>>
>>> >>>
>>>
>>
>
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups "Hobo
Users" group.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to
[email protected]
For more options, visit this group at
http://groups.google.com/group/hobousers?hl=en
-~----------~----~----~----~------~----~------~--~---
